//: Playground - noun: a place where people can play
/*第一章代码
 */
import UIKit

var str: String = "Hello, playground"
var number = 12
var rate:Double
rate = 12.0

var ratel = 12.0

print("胜率为\(rate)%")

var score = 20
 score += 3

let a = 3
let b = 2
let result = a+b

